


Moonlight Sonata

by LeVath, Reijin_Hakumei



Category: Bleach
Genre: Alternate Universe - Vampire, Canon Divergence - Post-Seireitei Invasion, Canon Divergence - Winter War, Character Turned Into Vampire, Explicit Sexual Content, Human/Vampire Relationship, M/M, Mating, Mating Bites, Mating Bond, Switching, Vampire Bites
Language: English
Status: In-Progress
Published: 2020-09-28
Updated: 2020-10-10
Packaged: 2021-03-08 04:47:38
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 7,808
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26700058
Author URL: https://archiveofourown.org/users/LeVath/pseuds/LeVath, https://archiveofourown.org/users/Reijin_Hakumei/pseuds/Reijin_Hakumei
Summary: In the wake of the three captain's betrayal, the Seireitei attempts to recover. In the midst of preparing for the upcoming war, strange new hollows appear with motives that are unclear.  Lieutenant Abarai becomes the first survivor of such an attack, the consequences of which none are prepared for. Can power gained from such a questionable source be trusted? Or is this just a ploy orchestrated by Aizen designed to destroy them from within?Excerpt:He didn’t like feeling like prey, and that’s exactly what this felt like. As if he were being hunted.He didn’t catch the movement. All of a sudden he was pinned to the ground, his left arm yanked back and what felt like several needles against his neck.“Lieutenant,” a voice rasped, the weight on his back shifting as the badge on his arm was twisted to be clearly read. He didn’t often wear it, but on missions it was expected, so that his rank would not be questioned. “Division six lieutenant… Yes, you will do…”
Relationships: Abarai Renji/Kuchiki Byakuya
Comments: 20
Kudos: 23





	1. Chapter 1

**Author's Note:**

  * For [SesshomaruFreak](https://archiveofourown.org/users/SesshomaruFreak/gifts).



“You must be wondering… Why am I still alive…”

His captain wasn’t even looking at him. Rather, his slate gray eyes were fixed on the deep blue of the sky, window open wide next to his hospital bed. Renji was seated across the room, a respectful distance away near the door to the hall. He tried to shake the ridiculous feeling that he was guarding his taicho while in his battered condition. 

Even in this state, Kuchiki Byakuya was not a man to be taken lightly. He was enduring this stay in the hospital mostly because he was well mannered and respected Unohana-taicho enough to remain on bed-rest, as she recommended. Well, for one day, at least. Renji knew the captain had already made plans to return to the division tomorrow. He would be weakened by his injuries for a time, but even a weakened Byakuya was far stronger than almost any other shinigami. 

Renji allowed his gaze to linger on his captain’s unusually troubled expression. He seemed so… unguarded, in this moment. Lost, even. “No way…” Renji said, his words careful but certain, “If you were to die… Who would I look up to and strive to defeat?”

Byakuya turned his head slightly, seeming to focus at nothing beyond the foot of his bed, but Renji knew he was actually watching him out of his peripheral vision. He had watched his captain for far too long, he knew all his tells… 

“Captain…” Renji began, looking down slightly as he searched for the words that would best reach him in this moment, words that he needed Byakuya to hear, to accept, to understand. Words that, just maybe, in his unsure state, he’d be _able_ to listen to… “I…”

**“RENJI!!!!”**

Kurosaki Ichigo. Of all the terrible moments… Kurosaki Ichigo had burst through the open window against which Byakuya’s bed had been positioned. Byakuya’s eyes widened in complete surprise and the expression would have been comical to Renji had he not been so angry with Ichigo’s intrusion.

 **“BE QUIET!!”** Renji snarled at him, closing the distance between his position at the door and Byakuya’s bed in the space of a heartbeat.

“Oh?!” Ichigo gasped out, taken aback by the severe tone coming from the usually laid-back red-head. 

“What do you want…?” Renji continued, his tone barely any better, “I was in the middle of saying something nice…” What he was actually going to say he had no idea, but that wasn’t the point.

“O… Oh… Sorry…” Ichigo mumbled before collecting himself. “Do you know… where Rukia is?” This time the question was at least asked with a modicum of decorum and not shouted for half of the hospital wing to hear.

“Huh?” Renji said, completely thrown. “Why, did something happen to her?”

“M… Meh. Never mind if you don’t know.” Ichigo said, still a bit sheepish at Renji’s odd behavior, the hand that wasn’t supporting him on the window waving dismissively between them. 

“Kurosaki-kuuuuun… It’s dangerous to climb up to the third floor window, you know?” Orihime’s sweet voice said as she peaked over the sill next to him.

“WHAT THE!?” Ichigo exclaimed, immediately focused on her trembling body as she tried to hold herself up against gravity next to him, “What about you!? Come to think of it, how did you get up here!?”

Ichigo glanced back inside before hastily dismissing them, “Sorry, Renji! Byakuya! We’re out of here.”

Orihime politely chimed in, “Sorry to bother you, Renji-kun, Byakuya-san.”

The two fell back to the ground and Renji watched as they ran off. “...What the hell is up with those two…?”

He looked back at his captain, who had his hand to his chin, his slate gray eyes cast downward. “What’s wrong, captain?” he asked, the expression odd as he was usually so closed off. He was glad to note that Ichigo’s interruption hadn’t caused his taicho to retreat into himself again. Renji much preferred being able to watch the expressions flit across his handsome face and... 

…and Renji realized… Byakuya’s slate gray eyes were focused on the place where Renji’s knees were brushing against Byakuya’s legs, stretched out beneath the blanket on the bed. Renji hadn’t really noticed that he’d kneeled there in his scramble to grab Ichigo and stop him from further inconveniencing his taicho. He felt his cheeks heating as he now fully felt the contact. 

“Nothing…” Byakuya said in contemplation, looking up into Renji’s dark brown eyes. They just stared at each other for several moments before Byakuya frowned, asking, “Is that man… going to address me by my first name from now on?”

Renji stilled, blinking at his taicho, before laughter bubbled out of him and he stood back on the ground beside the bed. “Yeah, probably. He doesn’t seem to care about titles much.”

Renji turned to return to his seat by the door, his captain's voice halting the movement, “Renji…”

“Captain?” he asked as he looked back at Byakuya. His slate gray eyes were locked on him, capturing his own dark brown as he turned and he couldn’t help but feel the blush returning to his cheeks. It was unfair how beautiful his captain was, you would have to be blind not to see. 

Renji had never even remotely entertained the thought of pursuing him though - his captain didn’t seem to want to become close to anyone and he doubted, after being _married_ to a _woman_ when he was younger, that a Rukongai street rat who was also a _man_ would be his captain’s first choice. And Byakuya could have almost anyone he wanted. Leader of the Kuchiki clan, still young, a captain, smart, powerful, and utterly beautiful. 

Renji wasn’t a fool. 

He knew his place.

Still… the beauty of the moon deserved to be looked upon, even if you knew you would never reach it.

“That boy… He addressed you as Renji…”

Renji turned to face his captain fully as he said, “Well, yeah, like I said, Ichigo’s not one for titles. I don’t really mind.”

“Are we not more familiar? _Renji?”_ It was all Renji could do not to shudder at the emphasis Byakuya placed upon his first name.

“I… Well, I should think so. I have been your lieutenant for these past three months and we’ve mostly been together almost every day for that time…”

Byakuya’s piercing gray eyes narrowed slightly, “And yet… you address that boy, a boy you have known less than a month… A boy that, until recently, was an enemy… You address him with more familiarity than you address me…”

Renji’s eyes widened and he stepped closer, hand almost reaching forward but he caught it in a fist as he declared, “I only address him that way because he _asked_ me to. I am not blind to your station, and I know to give you the respect you rightly deserve. The two are not comparable in the least. Kuchiki-sama, I -”

“Renji.”

Renji paused in his admittedly flustered yet passionate reassurance. He had no idea why his captain thought he was more familiar with Ichigo than himself…

He’d been aware of Kuchiki Byakuya long before becoming his lieutenant.

Ever since that day… That day Rukia left him behind… 

He’d worked so hard, and Byakuya became the man he measured himself against. He knew he’d always come up short, that he’d never be able to reach the cold moon aloft in the lonely black sky… But that was the goal he chose for himself.

He hadn’t planned on falling in love with him.

That’s why his words cut him so deep. He had buried those feelings deep within him, ignored them, and was for the most part successful. But he was sure the captain was aware that Renji felt strongly for him, though the nature of those feelings Renji very carefully concealed. How could he suggest that _anyone_ could take his place as the center of Renji’s focus?

He stilled, awaiting whatever his captain had to say, but the fire in those dark brown eyes still burned in indignation.

“Renji,” Byakuya repeated, his voice steady, “I would like you to address me as Byakuya… At least when we’re alone like this. I think you have more than earned the right to do so…” Byakuya glanced back to the covers, averting his eyes in what could only be shame, “Especially after my earlier actions. You are my lieutenant… And Rukia is family… 

“I chose wrong. I will not apologize, you don’t deserve such empty words. But I will acknowledge my error. In the future, I will endeavor to weigh your words more heavily.” 

Renji was floored. This had really shaken his captain, he could see it clearly now. The unguarded expression, the annoyance over Ichigo’s easy familiarity… It all stemmed from this. He regretted his decision to choose the law over his family - a law they now knew was utterly fabricated to begin with. There was no Central 46, no current governing body, hadn’t been for a while - for how long was still being investigated. And yet, only Hitsugaya-taicho had thought the orders suspicious enough to investigate. Byakuya was clearly tearing himself apart over it and Renji now suspected that the reason he had agreed to this day in bed was not to only allow his physical body to recover. 

“Thank you,” Renji said simply, knowing that saying anything else right now would do little good. “Byakuya,” he added, acknowledging his captain’s request. Slate gray eyes found and held dark brown briefly before nodding, his gaze returning to the blue sky outside the window. Renji retrieved the chair by the door, setting it next to the bed.

And if he allowed his hand to rest near Byakuya’s leg… And if Byakuya shifted ever so slightly so that they touched and warmth traveled between them… 

Neither of them mentioned it… 

…Both lost within their own thoughts.

* * *

It was an odd feeling, peacefully bidding farewell to the four teenagers led by a cat that had so suddenly and rather violently changed everything about their lives in just two short weeks. Odder still was the feeling that nothing had really changed as Renji and his captain returned to their division.

Dark brown eyes flickered to the petite woman that followed a step behind her brother. No, that was a significant change. Before, Rukia had barely set foot in the sixth division even though her brother had been captain here for the entire time she had known him. Even though he had adopted her - why, at the time, had been a bit of a mystery - he kept her at a distance. Renji knew he actually did check up on her, he’d seen reports from Ukitake-taichou that detailed her progress and state of well-being within the files of the sixth division’s office. They were very organized, dating back to her time in the academy. 

Renji hadn’t understood back then, why his captain was so fixated on Rukia of all people. Afterall, they had grown up together, joined the academy together, and neither had done anything at that point to gain the attention of the leader of a noble house. But it was clear that Byakuya _did_ care about Rukia’s progress and well being. Renji had been determined to figure it out, at first for Rukia’s sake - out of concern - but then… it also became clear that it was because he simply wanted to know everything he could about the captain that had captured his heart with so little effort.

They knew the reason now. He had not been conscious to hear his captain's words at the time, what he had confessed on Sokyoku hill, but Rukia had found him later and told him what he had said. Rukia was Hisana’s sister, the woman that had been Byakuya’s wife for five years before succumbing to a very rare disease. Hisana hadn’t wanted Rukia to know… But… After everything that had happened, his captain must have felt like Rukia _should_ know. He had been far more open - with both of them - after that battle. It was nice, seeing the siblings become closer. 

Like real siblings. After nearly fifty years, it seemed long overdue.

Rukia was on leave from the thirteenth division for the remainder of the week as she still needed to recover. Byakuya should have been as well, but then his captain had never been one to be idle. He insisted he could rest just as well from the office and that allowing the paperwork to continue to accumulate would only cause more stress in the end. 

Just as they were about to enter the office, a Jigokuchō fluttered ominously between them, relaying a message from the head captain, “We have suffered the loss of two shinigami sent to investigate a hollow attack in Inuzuri. Abarai Renji is to conduct a follow-up investigation, as he is our most senior officer with knowledge of the area. The bodies of the victims are strange, unlike any hollow attack we have seen. Begin by examining the bodies and then find this hollow. Cleanse it if able, but take great care. We do not yet know how this hollow is killing its victims to leave the bodies in such an odd state.”

The worry he saw in Rukia’s eyes was expected… But even Byakuya’s expression held concern. If you knew what to look for.

And Renji did.

“I’ll stay here with nii-sama,” Rukia said, “Be careful.”

“Inform me as soon as you return, Renji,” Byakuya stated, as if it were an order.

Renji knew better though. _You had better return safely. And I want to know the moment you do._ His captain was in a rather delicate state right now, emotionally, which was something Renji never thought he would see. He would do all he could to make sure his captain found his conviction and inner peace again. Of course he would return safely, because Byakuya needed him to. And Byakuya would be the first to know.

Renji nodded to the siblings, giving a self-assured grin before using shunpo to head in the direction of Inuzuri.

Upon arrival, he did as instructed and immediately went to inspect the bodies of the victims. They were ashen white and somewhat shriveled… 

“All the blood has been drained from them,” the elderly woman that was charged with their care informed him. “We’ve never seen this before. Hollows feed on souls, they have no need for blood.”

It was indeed strange. But, if that was what this hollow was interested in, perhaps this was something he could use to lure it…

Renji purposely cut his palm with Zabimaru, allowing the blood to flow freely. He then proceeded to make his way out of town, wiping the blood on the sides of buildings he passed, as if to lead the hollow away. He wasn’t certain this would work but, if blood was what this hollow desired, hopefully doing this would force it to focus on him and leave the residents of Inuzuri in peace. Life was already difficult enough here. He would know.

He waited within the trees in the forest outside the district, as far away as he dared. Hopefully the hollow would be drawn here by his blood, but if not, he wanted to be able to hear any commotion from the district and be able to respond immediately.

Time passed and Renji did his best to remain focused, his captain’s words to return to him clear in his thoughts. It was late, the absence of the moon in the sky making the night darker, only starlight illuminating the forest around him. 

He tensed. He felt like he was being watched but he couldn’t sense anything. Dark brown eyes darted around the trees. He was in the center of a clearing and it would be difficult for him to be taken unaware, but he was still incredibly wary of the treeline. He didn’t like feeling like prey, and that’s exactly what this felt like. As if he were being hunted.

He didn’t catch the movement. All of a sudden he was pinned to the ground, his left arm yanked back and what felt like several needles against his neck. 

“Lieutenant,” a voice rasped, the weight on his back shifting as the badge on his arm was twisted to be clearly read. He didn’t often wear it, but on missions it was expected, so that his rank would not be questioned. “Division six lieutenant… Yes, you will do…” 

Renji screamed as the needle-sharp - were those claws? - retreated from his neck and his back was raked open in five very deep gashes. He struggled as he felt the hollow rub against the wounds, the pain agonizing, until he managed to break free. The hollow was a twisted thing, with vaguely human traits but they were _wrong,_ so wrong. There was hair, but the length was not consistent, and missing entirely in some sections of the head. The eyes were so offset it was unsettling, and left far larger than the right, though both glowed an eerie yellow. The mouth was all fangs, the canines longer and extending past the cut lips, dripping with its own blood. It was bleeding profusely, cuts and gashes littered it’s form. 

Renji gritted his teeth and unsealed Zabimaru. His back felt like it was on fire - more so than it would normally have from such a wound. It was concerning to say the least. He needed to take out this monstrosity and return to squad four immediately. 

The hollow was fast but taken by surprise as Zabimaru extended, the whip-like sword decapitating the disturbing creature with ease, shattering the bone-white mask that had wrapped around its neck like a collar. Renji sheathed Zabimaru and staggered on his feet. The burning of his back was becoming worse. He immediately fled towards the Seireitei as fire burned along his veins from the wounds on his back. Shunpo was not easy in this condition, his focus diverted with the pain, but he had to make it back.

His captain needed him. 

And so he would return.


	2. Chapter 2

Renji woke in a room much like Byakuya had stayed in, just a few days before, the bed against the wall, a breeze coming through the open window. He stared out at the blue of the sky, his thoughts hazy at first with sleep, until movement in his peripheral vision had him focusing on his captain seated beside his bedside. 

“Sorry,” Renji said, his voice still rough with sleep, “I had meant to inform you as soon as I returned…” 

Slate gray eyes searched dark brown, for what Renji couldn't say. After a moment those eyes rather pointedly glanced down, Renji's following, to see he had his captain's hand captured within his own in a strong grip, resting just below his chin. How had he not noticed? He immediately let go, flushing, but was saved from saying anything as Byakuya stood and stated, “I will inform Unohana-taichou that you are awake.” 

Renji watched him leave, feeling a bit warm inside that he had been concerned enough to sit by his side until he awoke, to allow him to hold onto him like that, no matter how embarrassing it was. He must have been in really rough condition for his captain to do so. He felt… fine… right now. Great, actually. 

He sat up, the blanket falling to his hips and baring his heavily bandaged chest. Odd, usually he would feel the stretch and pull of the wounds on his back. He remembered how deep they had been. But he couldn’t feel them at all.

Byakuya returned with Unohana more quickly than he had anticipated, both approaching the bed though Byakuya stopped several feet from it, giving the healer her space. 

Unohana had a frown on her face as Renji felt her healing kido wash over him. She paused, calling over Hanataro, her fourth seat, who had been timidly standing by the door. “Hanataro, please remove Lieutenant Abarai’s bandages, I need to confirm something.”

The small shinigami hastened to comply, giving Renji an apologetic smile as he reached for the ties on the bandages and unraveled them with quick, sure movements, despite his overall timid nature. He was good at his work and Renji couldn’t help but feel slightly fond about him after he had done what he could to help Rukia, even willing to be considered a traitor.

“Thank you,” Renji said softly to him, though he was sure the two captains were able to hear if they wished to, “for helping save Rukia.” Hanataro blushed but his hands remained steady and he looked a bit more self-assured than before.

When all the bandages were removed, Unohana politely requested Hanataro step back and Renji felt her hands and kido upon his back.

“I’m not sure how, but your wounds are completely healed, Lieutenant Abarai. In fact, you seem more healthy now than before you left for your mission, if a bit anemic from the loss of blood. I am uncertain as to the cause of such a quick recovery. How do you feel?”

“Great,” Renji said immediately, “Honestly, I haven’t felt this good in a long time.”

“Hm. Conditions have causes, Lieutenant. I don’t see a reason to keep you here under observation, what with your squad in desperate need of you, but do monitor yourself. Anything out of the ordinary, anything at all, you are to report back to me immediately. Do you understand?”

“Yes, mam.” 

Hanataro handed him his other clothing that had been removed in order to bandage his back and he received them with a nod and a quick, “thanks,” before he was left alone to dress. He couldn’t help but notice that his captain looked a bit drained, as if he hadn’t had much sleep. Could he have stayed with him that entire night, watching over him? Surely not, even if he was his lieutenant, Kuchiki Byakuya simply wouldn’t do such a thing for a subordinate. He would return to duty until he received word that he was needed. Even then, the likelihood of him showing up himself was rare. 

Usually Renji was sent to interview squad members after an attack. Surely Byakuya could have sent any of their seated officers to retrieve him in his stead and have him brought back to interview him in his office, as he always had before… Why was this situation different? Was it the oddity surrounding the hollow that had attacked him? Sure, he’d never encountered a hollow quite like it before, but it had been purified and killed by his zanpakuto easily enough.

He bowed to Unohana-taicho on his way out, following his captain back to the sixth division. After a quick exchange asking if Renji felt well enough to use shunpo - which he did, he really hadn’t felt this good in a long time - their pace greatly increased and it wasn’t long before they were back in their office, Byakuya taking his place behind his desk and gesturing Renji to stand where he always would to give his report.

He immediately went into recounting his mission, trying to remember every detail he could. If Byakuya was concerned enough to personally attend to him, there was something different about this case and any detail could be important. His eyes kept straying though from his taicho’s face to his neck, as though he could _see_ his pulse beat. He wasn’t wearing the ginpaku scarf today, nor the kenseikan in his hair. He looked far more approachable without either item proclaiming to the world his status within the noble Kuchiki family. Renji nearly laughed at the thought - that his stoic captain could ever be considered _approachable._

But then that wasn’t entirely unsurprising. Captain Unohana had wanted Byakuya to continue to rest for a few more days, in order for his reiatsu to fully recover, although she could not find any issue with allowing him to catch up on paperwork. Having both their captain and then their lieutenant laid up in the fourth division couldn’t be doing any good for morale. Renji felt fine now though, and he was itching to do some training rounds. He always did enjoy a good fight, but now it almost felt like a compulsion.

“I don’t remember much after starting to shunpo to the fourth…” Renji concluded. 

Byakuya was silent for a minute, seemingly thinking, his long, elegant fingers interlaced in front of him, his lips just brushing the knuckles as he was slightly leaned forward. Renji was hyper aware of every detail, the controlled breath, the slate gray eyes as they gazed unseeingly at the surface of his clean desk, the slight tension there as he thought. 

The minute seemed to stretch into several eternities for Renji, so much so that he startled when his captain finally spoke, “I was summoned to the fourth upon your arrival… You didn’t seem to be responding to anything the healers asked you. You were… catatonic, though your eyes were open and you could walk on your own, you didn’t seem to actually hear or see anything, as if you were unable to focus. I’d never seen anything like it.

“You followed my directions, at least, enough to sit on the bed and not resist the healers as they examined you. You hissed at them at first, when they tried to remove your clothes to attend to your back, but you allowed me to do so. You were hot to the touch, like you were burning, and you were continually leaning into me, whimpering, saying that it hurt, asking me to make it stop. 

“I… I did not know what to do Renji. I had never seen anything like it before. It was as if the human part of your mind was absent. You trusted me, but not anyone else. You became distressed if I moved away at all, and your eyes… They were vacant and yet they followed me and you only listened to directions if I gave them. 

“I could not do much more other than try to keep you calm while the healers addressed the wound on your back. It really should not have healed as quickly as it has… Those claw marks were very deep, into the muscle, even scraping some of the back ribs. The healers weren’t sure how you were even able to walk properly. They did what they could but the wound was resistant to healing kido, and instead they resorted to simply bandaging it up.

“I tried to leave then, to allow you to rest, but you grabbed my hand and held it like a vice. You didn’t hurt me but I didn’t think I could make you release me without hurting _you,_ so I asked one of the healers to bring me a chair and sat beside you. You brought my hand up to your nose and… I think you breathed in my scent? That seemed to calm you and you finally went to sleep, though you still would not release my hand and kept it nuzzled against your nose as you slept. 

“You were still burning up, as though a fever had taken over your entire body, but the healers said there wasn’t anything more they could do other than hope it broke on its own as you weren’t responding at all to the kido. I got as comfortable as I could and drifted in and out of sleep. You never did release my hand, not until you woke up and were, well, _you_ again. 

“And you seemed completely fine. Your fever had broken, the wound on your back had healed… You no longer seemed to be acting strangely or even remembered doing so… Renji, something happened to you. I think Unohana-taicho’s advice needs to be well heeded. Anything unusual, we need to take careful note of it. We also need to make the other squads aware of the peculiarities of the hollow you encountered and to be cautious when engaging them, if any more remain. The fact that it commented on your status as a lieutenant is what concerns me the most… This may have been a targeted attack on us, not simply a chance hollow appearance…”

Renji was stunned at his captain’s recounting of events, given in his usual, steady voice, void of anything other than fact. Except… It _wasn’t._ Renji could hear the slight changes in pitch and tone that he wouldn’t have before. Byakuya had been shaken by this, and was greatly concerned - just good at hiding such things, both due his position as captain and as head of the Kuchiki family. To realize his captain had been _worried_ about him… He pushed that aside, there were more pressing things to address.

“You are thinking Aizen may have sent that hollow.”

“It is a possibility we need to be aware of. He may send more. With the Hogyoku at his disposal, we don’t know all he’s capable of. However, I think it can be safely assumed that hollow experimentation would definitely be a project he would undertake, as he and the other traitors escaped to Hueco Mundo. It would be folly to follow him there without more information. We have sent teams to Hueco Mundo in the past - none returned.”

Renji frowned, his expression serious, as he nodded. “Captain… Byakuya,” he corrected, noting his captain’s slight change in expression, the slate gray eyes tensing and then relaxing. How odd, that such a simple thing as how Renji addressed him seemed to matter to him. Not long ago, Renji would have thought the other would see casual address as a form of disrespect. He was beginning to think, however, that there had been a lot he had been wrong about in regards to his stoic captain. The man was nearly impossible to read, but Renji found that after whatever that hollow had done to him, he was now able to pick up on the subtle gestures that gave him away. “May I resume my duties? I will do as instructed and take note of anything weird or unusual but I’ve honestly never felt better and our men need to see at least one of us out there and well.”

Byakuya was about to argue, he could tell from the slight tension in his lips, but then he said instead, “I will trust your judgement, Renji. It is true that our squad morale has suffered and seeing you well would greatly improve our men’s focus. I will write the report and send it to the other captains. Make sure you stay within the training grounds visible from this office, however, just in case. I’ll be looking in on your condition from time to time.”

Renji nodded. He was referring to the large window behind his desk that oversaw the main training grounds. It was on the upper floor, impossible for those training to see into, but it afforded the captain the ability to watch their progress without them knowing he was watching. It helped with discipline, Renji supposed, that they could be observed at any time without knowing. It certainly helped him put in more effort, knowing that his captain could be watching as he trained at any time.

Renji knew he was dismissed but he was hesitating. He didn’t know what to say about what Byakuya had told him concerning his unconscious actions the previous night. He felt like it _should_ be spoken about but he had no idea how to bring the subject back up, or really what to say about it. He had been so… relieved to see Byakuya there when he awoke. He could tell, one of the reasons he was so calm right now about everything was directly a result of his captain’s presence. He wasn’t sure what leaving him would do to his state of mind… Even the consideration of the act - walking out of the room without him - was bringing a hint of anxiety to his mind… 

Not finding the words and beginning to feel awkward, he gave a slight bow and turned resolutely for the door. He was just going to train… And Byakuya would even be watching over him. There was nothing to feel anxious about…

The men were very relieved to see him and welcomed him wholeheartedly as he joined them on the training grounds, watching spars, giving advice, and participating in spars himself. Every now and then he _felt_ like Byakuya was watching him, although such a thing should have been impossible for him to sense. Even out of his sight, he seemed aware of his captain. 

He also _knew_ Byakuya was still in the office. He had no idea how but he was certain of it, like a low-level awareness that tugged at his mind and, if he focused on it, he just knew what the other was doing. It was fuzzy, and it didn’t come with images or sounds just… a _knowing._ Not unlike sensing a killing intent… Except this awareness was focused completely on his captain’s whereabouts and actions. 

Renji figured this definitely qualified as an oddity to take note of and resolved to inform Byakuya as soon as he had finished his observations of the men on the training grounds. Sparring had brought other revelations. He wasn’t really faster… At least, he didn’t think he was, but others seemed to be moving in slow motion. 

He was able to dodge literally every attack with ease, and counter in their blind spot before they were aware he had moved. To the men, it looked like he was getting insanely lucky, seemingly dodging the correct way before the attack was even launched, but it was just too obvious in reading the minute tells in their actions what they were about to do and his body reacted accordingly. And so Renji added this new level of observational ability and improved reaction time to the ever growing mental list of oddities. 

Kido had been another revelation. He had _always_ overpowered his kido spells, blowing up either the target or himself, but he could now _feel_ and _control_ his reiatsu in a way that it was laughably easy. He didn’t understand why he’d had such a difficult time before - of course forcing that much reiatsu into his kido had resulted in disastrous consequences. His senses were greatly heightened, including, apparently, his ability to sense reiatsu. And so another oddity was added to the list.

If this was some scheme Aizen had dreamed up, Renji couldn’t help but think it was a complete failure on his part. Renji felt _stronger_ and far more capable with these heightened abilities. What would be the purpose in making the enemy more powerful?

By the time Renji left the training grounds, he was sweaty, his kosode half open and hanging from his obi, leaving the left half of his torso bare. He felt overly hot, for some reason, and _thirsty,_ although even the thought of water made his stomach turn. He thought little of his state of dress as he returned to the office to inform his captain of everything he had taken notice of, after all it wasn’t unusual for him to remove his kosode during training. Usually though it was because it had been damaged beyond a point where it could really still be worn… 

Today no one had been able to land a single blow on him.

Byakuya didn’t seem to be disturbed by his appearance as he entered the office and closed the door behind him, collapsing on the couch just to the right of the door. Walking into the room, he’d been hit by a scent that all of a sudden made him extremely dizzy, and he found himself breathing through his mouth instead, the scent completely overwhelming to him. He whimpered, panting as the heat inside him grew, feeling shaky and weak, so suddenly that he hadn’t even noticed his captain approach until a cool hand was on his forehead. 

Renji found himself pushing up into the hand, a whine issuing from the back of his throat, as dark eyes locked onto the pulse point he could see upon his captain’s neck. The scarf was back and Renji decided that he hated the item - it was in the way. Though the action seemed slow to Renji, it must have been exceedingly fast to catch Byakuya so off guard that he was able to pin his captain down on the other sofa, deftly clearing the table between the two, tugging the offending item down to expose his neck completely, mouth watering at the sight.

Byakuya was completely still underneath him as he said, commandingly, “Renji.”

Renji froze and then whined, his nose fully taking in that incredible scent that he now realized was his captain as he nuzzled into the neck beneath him, his tongue darting out to lick the smooth skin. “Please, Byakuya,” he gasped out, “you smell so good. And I’m so _thirsty.”_

Byakuya was still motionless beneath him, although his fingers were digging into Renji’s hard biceps as they flexed with the effort it took to restrain himself from biting down on his captain’s neck. His teeth felt longer, sharper, as though he had fangs, and he cut his own tongue by running it over them, his own blood filling his mouth and making him moan, but it did nothing to slake his thirst that was overwhelming his mind. 

Byakuya’s breath hitched at the moan. Had his senses not been heightened and so focused on his captain, it wouldn’t have been perceptible. Renji clutched him more tightly, his right hand still pinning Byakuya’s left shoulder to keep him in place as his left hand wound around his neck, tilting his head back by tugging gently on the long raven hair so that the smooth skin was bared, dark eyes locked on the pulse point and his mouth open, panting in harsh breaths. 

He leaned down, his new, sharp teeth grazed at the skin, catching, tearing, and causing beads of blood to form that he caught on his tongue. The sound he made, as soon as Byakuya’s blood hit his tongue, was utterly wanton and lewd as he bathed his captain’s neck in his saliva, whimpering at what he wanted being so utterly close and yet still having the presence of mind to not actually bite without being given permission. 

He had no idea _why_ he was doing this, he wasn’t entirely in control of his own actions and it scared him a bit. But he also knew that, if he wanted to, Byakuya should be able to overpower him… Right? So… Why wasn’t he?

Byakuya’s scent had changed slightly, it was _deeper_ somehow, more earthy, and Renji realized it was tainted with _lust._ Byakuya wasn’t fighting him because he wasn’t entirely certain he wanted to… He was _enjoying_ this… Not that he’d ever admit to such a thing, but Renji could now tell. When it came to his captain, the other could no longer hide anything from him. 

Certainly not desire. 

“Taicho…” Renji growled, low, _“Please_ _Taicho… Byakuya…”_

Byakuya was still tense, clearly thinking, considering, but then he relaxed and gave the barest of nods. It was all the permission Renji required. He carefully bit into the neck, allowing the blood to collect in his mouth, savoring the taste before swallowing it down. He moaned, feeling flushed and desire racing through him, making him rapidly harden. Considering that may be too much for his captain to be comfortable with, he effortlessly shifted them so that he was kneeling on the sofa, knees slightly apart for Byakya to be cradled between them and leaning back, Renji’s right arm supporting him as he continued to drink from his neck. 

He wasn’t getting any friction this way where he desperately wanted it but the last thing he wanted was for Byakuya to become uncomfortable with the situation, if he was even completely comfortable with it to begin with. He seemed to be enjoying it though… The lust in his scent had only deepened, his breathing and pulse had increased, and if the man wasn’t so stoic Renji bet he would have been moaning as well. 

“Renji,” Byakuya said softly, and Renji forlornly withdrew from his neck, lapping at the twin bite marks that were rapidly scarring over, a smugness he didn’t understand flooding him, seeing the marks. _He_ had left those, Byakuya had allowed _him_ to mark him. And Byakuya was _his,_ he knew it. Knew it more strongly than his own name. As if that fact were more vital to his identity.

Byakuya was panting, like Renji had been, and he was incredibly flushed, heart racing, and that scent was heedy. Byakuya wouldn’t ask… Perhaps he couldn't ask for what he obviously needed… But Renji knew.

He always knew.

“Byakuya,” Renji murmured, his left hand petting along his taicho’s thigh, trailing to press against his lower abs, tracing lazily. If he directly asked, Byakuya’s senses would likely return to him, and that was the last thing Renji wanted. His captain never asked for anything for _himself._ Always only doing what duty demanded of him. But the question was clear in Renji’s actions and with a shuttered breath, molten steel eyes locked with dark mahogany brown, Byakuya gave that slight nod that Renji was growing to adore - not that there was really anything he didn’t adore about this man - and Renji smiled, fanged teeth catching on his lips, as he allowed his hand to drift lower. 

Byakuya was so achingly hard, and thick, and long in his hand and Renji’s eyelids dropped at the feel of it. What he wouldn’t give to feel that inside him, to feel it against him as he sunk into his beautiful taicho… Whatever the other would allow, he wanted every part of him. Renji was far from innocent but he’d never wanted anyone more than this man, had never _felt_ this way for anyone else, this need to be owned and to own in return. He’d felt it before the attack on him, but it was far more amplified now. 

He needed to feel him, needed to touch, to have his arousal within his hand, and without another thought he slipped his hand within his hakama, groaning at the soft hardness in his grasp. Byakuya had arched at the action, the barest noise coming from the back of his throat. Renji leaned down, peppering light kisses and licking across what skin he could reach. Considering he was still in his kosode, it wasn’t nearly as much as he wanted, so his lips traveled up instead as his hand pumped him, reveling in the feel of his captain’s tremors beneath his lips.

He was kissing along Byakuya’s jaw when the other turned his face suddenly, Byakuya’s lips brushing against his own, catching on a fang and causing drops of blood to blossom on his lower lip. Renji immediately sucked the lip into his mouth, careful not to damage it further, and finally, _finally,_ Byakuya moaned brokenly into him.

His taicho was a bit more vocal now, Renji breathing out his captain’s name as he released him to watch the expressions that were now freely shown upon his face. He increased the pace of his hand as Byakuya’s trembling increased in his hold, relishing in his breathy moans, quiet still but unfiltered, the sounds going straight to his own arousal that he was studiously ignoring. This was about his captain, and Renji was amazed the other was allowing him to pleasure him in this way. 

Byakuya suddenly gasped out, “Renji…” and dark eyes watched, utterly captivated, as his taicho shuddered as he came, Renji’s hand pumping him through it. Renji had never seen something so utterly errotic as his captain’s expression when he finally let go, his molten steel eyes locked onto his own, knowing exactly who was doing this to him and accepting, welcoming his touch. Renji was flying high and completely content, his own arousal easy to ignore, his full attention captured by the beautiful man in his grasp and what _he_ needed.

Almost on instinct, Renji collected all he could of his captain’s release with his fingers before removing them from his hakama and cleaning them off with his tongue, eyes fluttering and whimpering at the taste. It was even better than the blood had been, if he were being honest. 

“Renji,” Byakuya called to him, a question in his voice that Renji’s sensitive hearing had no problem picking up on. He was shaking and Renji quickly realized that, between the blood loss, the orgasm, and still being in general recovery, his captain needed him to take care of him. 

He easily lifted him, nuzzling against his jaw with a slight purr before using shunpo to bring him to his lieutenant’s quarters. Byakuya had his own quarters, of course, but Renji knew for a fact that room was empty, his captain staying at the Kuchiki estate when he didn’t fall asleep at his desk. Not that anyone other than Renji had ever seen him do such an undignified thing. 

He snuggled his captain into his own futon, wrapping him in his own blankets, all the time his mind catching on the word _mate. Must take care of mate._ He was only gone a minute, Byakuya remaining exactly how he had left him with his eyes closed and still shaking, returning with food and water. He wasn’t remotely tempted by either but he knew it would help his taicho to eat and drink. 

He propped his bundle against his chest, those slate gray eyes opening to narrow at him as his arms were trapped within the blankets. “Let me,” Renji said, nuzzling his jaw again and issuing that slight purr. Byakuya frowned but nodded and Renji proceeded to take care of him, feeding him and gently making sure he drank all the water. Slowly the shaking subsided and Renji, removing his kosode entirely, slid to lay next to him on the futon. 

Byakuya watched him before shifting around, unwrapping the blanket and throwing it over the both of them. Renji smiled, pulling his captain… _mate…_ against his chest, that purring sound gently rumbling at Byakuya’s acceptance and allowing him to take care of him. He could be notoriously stubborn, after all.

“Renji,” Byakuya murmured, “We need to talk about this…”

“In the morning?” Renji pleaded, his grip tightening on him, afraid the other would pull away. He was nearly panicked at the idea that Byakuya would leave.

Byakuya assessed him with those observant gray eyes before relaxing against him again. “Fine Renji, in the morning.”

Renji smiled, his nose nuzzling in the long raven locks, the purr coming from his chest the loudest noise in the otherwise silent room, lulling them both to sleep.

**Notes for the Chapter:**

> HAPPY BIRTHDAY HIME!!!!!!!!!!!!!!!!!!!!!!!!!!!!! WE LOVE OUR RENBYA PRINCESS!!!!!!!!!!!!!!!!!!!!!!!!!!!


End file.
